Hyponaetremia Flashcards

1
Q

What is Hyponatremia?

A

Serum Sodium < 136mmol/l

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the symptoms of Hyponatremia?

A

They are caused my decreased ECF osmolality so water does intracellular - this causes cerebral oedema and:

  • Lethargy
  • Confusion
  • Coma
  • Convulsions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the causes of hyponaetremia?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the role of ADH/Vasopressin in hyponatremia?

What does it do?

A

It is released in times of stress or dehydration and causes the following things:

V1 - Vasoconstriction

V2 - Increased water uptake via aquaporins

Net effect of retaining fluid and keeping BP up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can true volume depletion and high ADH lead to hyponatremia?

A

Vomiting and diarrhoea causes volume depletion and release of ADH - can lead to hyponatremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is hypervolemic hyponaetremia?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does ecstasy lead to high ADH and hyponatremia?

A

It directly increases ADH and increases thirst which leads to hyponatremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does SIADH lead to high ADH and hyponatremia?

A

Related to lung diseases and increased ADH levels causes relative hyponaetremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does marathon running lead to increased ADH and hyponatremia

A

Exercise stimulated ADH despite loss of salt in sweat.

This plus increased water uptake causes hyponaetremia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What could be the causes hyponatremia and low ADH?

A

Polydypsia eg alcohol

Renal failure - not responding to ADH so it stops being produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What physical signs may suggest hyponatremia?

A

Nausea

Confusion

Lethargy

Postural hypotension (due to fluid in cells)

Reduced skin turgor (loss of free water)

Oedema/ascites (if SIADH or LF, HF N.B less barorecptor activation despite high fluid levels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What would urine osmolality be in hyponatremia?

A

High if trying to get rid of water eg SIADH

Low in may be low in polydypsia or volume depletion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What would the blood results be for SIADH?

A

LOW serum oslomality

LOW serum sodium

LOW blood urea (it is diluted)

HIGH urine osmolality (no water)

HIGH urine sodium (not reabsorped)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do you treat hyponatremia?

A

Treat underlying cause

Fluid restriction if needed

Fluid if volume depleted

Salt replacement

Loop diurtic in SIADH to reduce medullary osmolality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do you do in severe hyponatremia

A

Hypertonic solution and ADH receptor antagonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What would urinary sodium be like in hyponatremia caused by SIADH?

A

High as water absorbed

17
Q

How do you treat SIADH?

A

Loop diuretic to decrease medullary osmalility

18
Q

What is the difference between loop and thiazide diuretics?

A